Advances in protein microarray-based proteomics for gastric cancer applications in biomarker discovery, molecular subtyping, and precision oncology.

Gastric cancer remains a major cause of cancer-related mortality worldwide, largely due to late diagnosis and pronounced molecular heterogeneity. Although genomic and transcriptomic studies have advanced understanding of gastric tumor biology, they do not fully capture dynamic changes in protein expression, post-translational modifications, and signaling activity that directly regulate cellular function. High-throughput proteomic technologies, particularly protein microarrays, have emerged as powerful platforms for systematic protein profiling in complex biological samples. These technologies enable the simultaneous quantification of hundreds to thousands of proteins with high sensitivity and minimal sample requirements, supporting both discovery and translational research. Recent applications of protein microarrays in gastric cancer include biomarker discovery for early diagnosis, molecular subtyping, characterization of the tumor microenvironment, and assessment of therapeutic response. Multi-protein biomarker panels and integration with computational approaches have demonstrated improved diagnostic performance compared with conventional single-marker assays. In addition, proteomic profiling has provided insights into key signaling pathways and immune-related mechanisms underlying tumor progression and drug resistance. This review summarizes the principles and major formats of protein microarray technologies and highlights their applications in gastric cancer. Current challenges and future directions for clinical translation are also discussed.